The type of gateway support to use.
Should be a symbol specifying how to get a connection from the local machine.
Currently supported methods:
`telnet': Run telnet in a subprocess to connect;
`rlogin': Rlogin to another machine to connect;
`socks': Connect through a socks server;
`tls': Connect with TLS;
`ssl': Connect with SSL (deprecated, use `tls' instead);
`native': Connect directly.